<div>
    If this option is checked, Jenkins will schedule and execute multiple builds concurrently (provided
    that you have sufficient executors and incoming build requests.) This is useful on builds and test jobs that
    take a long time, as each build will only contain a smaller number of changes, and the total turn-around
    time decreases due to the shorter time a build request spends waiting for the previous build to complete.
    It is also very useful with parameterized builds, whose individual executions are independent from each other.

    <p>
    For other kinds of jobs, allowing concurrent executions of multiple builds may be problematic,
    for example if it assumes a monopoly on a certain resource, like database, or for jobs where you use Jenkins
    as a cron replacement.

    <p>
    If you use a custom workspace and enable this option, all your builds will run on the same workspace,
    thus unless a care is taken by your side, it'll likely to collide with each other.
    Otherwise, even when they are run on the same node, Jenkins will use different workspaces to keep
    them isolated.

    <p>
    When Jenkins creates different workspaces for isolation, Jenkins appends "@<I>num</I>" to the
    workspace directory name, e.g. "@2".  The separator "@" can be configured by setting the system property
    "hudson.slaves.WorkspaceList" to the desired separator string on the Jenkins command line. 
    E.g. "-Dhudson.slaves.WorkspaceList=-" will use a dash as separator.
</div>
